1. Field of the Invention
The present invention relates to a microscope system for obtaining an image having a wide view angle by repeatedly capturing an image while moving a stage, and by connecting obtained images having a small view angle.
2. Description of the Related Art
When a sample is observed with a microscope, the area of the sample that can be observed and shot at one time is mainly determined in accordance with the magnification of an objective lens. If the magnification of an objective lens is high, a high-definition image can be observed even if an observation area becomes narrow.
In a method mainly used for pathological diagnosis or to obtain material for a study, a sample image having a wide view angle is obtained at a low magnification. Thereafter, a portion of the image which is desired to be obtained in detail is specified, the objective lens is switched to a high magnification lens, and the image of the specified portion at a high resolution is obtained. In this case, if the view angle is narrow, still images having a small view angle are repeatedly shot while a stage is moved, and the obtained images having a small view angle are connected so as to obtain a synthesized image having a wide view angle.
A motorized microscope where a stage is electrically controlled in this way is known as a so-called virtual microscope system. However, since motorized microscopes are expensive, users who are accustomed to microscope operations tend to avoid using them. The following are techniques related to such virtual microscope systems.
Japanese Laid-open Patent Publication No. 2007-24927 discloses a technique for moving a stage in the vertical direction (X-Y) and a rotational direction (θ) with respect to an optical axis, for determining the coordinates of the position of the stage, and for synthesizing partitioned images having a small view angle.
Additionally, Japanese Laid-open Patent Publication No. 2005-266718 discloses a technique for specifying a portion desired to be observed in detail by recognizing an image shot at a low magnification as a parent image, and for recording the position of the parent image with respect to a certain child image by recognizing a partitioned image having a high magnification as the child image.
Furthermore, for image construction, there is a problem in terms of image quality wherein the seams of partitioned images shot within a small range are conspicuous in a synthesized image. As a method for improving this problem, Japanese Laid-open Patent Publication No. 2001-274973 discloses a technique for removing unevenness in brightness levels by making a lens distortion correction and a shading correction when partitioned images are obtained at a high magnification. This publication also discloses that unevenness in brightness levels is made inconspicuous after a synthesized image is generated by providing an overlapping portion between partitioned images with an optical flow method.